The invention relates to the use of compounds in combating fungi in plants.
In Bull. Soc. Chim. France, 1970, (10), 3630-6, there are disclosed certain thienopyrimidines. We have discovered that at least one of these compounds has utility in combating fungi.
In WO97/02262 there are diclosed thienopyrimidine derivatives, useful as fungicides, substituted at the 2-position by an oxygen, sulfur or nitrogen.
In EP0665224 there are disclosed two specific 2-benzyl substituted thienopyrimidines useful as fungicides and/or herbicides.
In WO99/14202, published after the priority date of this application, there are disclosed 2-substituted thienopyrimidines useful as fungicides.
The invention provides the use in combating fungi of compounds of general formula I 
wherein
R1 is hydrogen, hydroxy, acyl, acyloxy, optionally substituted amino, Ra, Ra3Si, RaS or RaO, where Ra is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted aryl or optionally substituted heterocyclyl;
Z is oxygen or sulfur;
M is a thiophene ring; and
R3 and R4, which may be the same or different, have have the same meaning as Ra or can be optionally substituted amino, hydrogen, halogen, cyano, nitro or a group ORc or S(O)mRc, where Rc has the same meaning as Ra or is hydrogen or acyl and m is 0, 1 or 2; or R3 and R4 together with the atoms to which they are attached form an optionally substituted carbocyclic or heterocyclic ring;
together with tautomers of compounds where R1 is hydrogen.
Most of the above compounds are novel, and accordingly the invention includes any novel compounds of formula 1 as defined above, including in particular, 7-bromo-3-methyl-3,4-dihydrothieno[3,2-d]pyrimidin-4-one.
Any alkyl group present in the molecule is preferably of 1 to 10 carbon atoms, especially of 1 to 7 carbon atoms, and particularly of 1 to 5 carbon atoms.
Any alkenyl or alkynyl group present in the molecule is preferably of 2 to 7 carbon atoms, for example allyl, vinyl or propargyl.
Any cycloalkyl, cycloalkenyl or cycloalkynyl group present in the molecule is preferably of 3 to 7 carbon atoms, especially cyclopropyl, cyclopentyl, cyclohexyl or cyclohexenyl.
Substituents, when present on any alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl cycloalkynyl moiety may for example be halogen, cyano, optionally substituted alkoxy, optionally substituted alkylthio, mercapto, hydroxy, nitro, optionally substituted amino, acyl, acyloxy, acylthio, optionally substituted phenyl, optionally substituted heterocyclyl, optionally substituted phenylthio, optionally substituted phenoxy, optionally substituted heterocyclyloxy, optionally substituted heterocyclylthio.
Cycloalkyl, cycloalkenyl, cycloalkynyl groups may also be substituted by optionally substituted alkyl, alkynyl or alkenyl and vice versa.
Substituents when present on any phenyl or heterocyclyl group may be the same or different and include Ra-(X)n-, (where Ra is as defined above, X is oxygen or sulfur and n is 0 or 1), optionally substituted amino, hydroxy, halogen, cyano, nitro, acyl, or two adjacent groups together with the carbon atoms to which they are attached can form an optionally substituted benzo or heterocyclic ring. Heterocyclyl groups may also be substituted by double-bonded substituents such as oxo or imino.
The term heterocyclyl includes both aromatic and non-aromatic heterocyclyl groups. Heterocyclyl groups are generally 5, 6 or 7-membered rings containing up to 4 hetero atoms selected from nitrogen, oxygen and sulfur. Examples of heterocyclyl groups are furyl, thienyl, pyrrolyl, pyrrolinyl, pyrrolidinyl, imidazolyl, dioxolanyl, oxazolyl, thiazolyl, imidazolyl, imidazolinyl, imidazolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, pyranyl, pyridyl, piperidinyl, dioxanyl, morpholino, dithianyl, thiomorpholino, pyridazinyl, pyrimidinyl, pyrazinyl, piperazinyl, triazinyl, thiazolinyl, benzimidazolyl, tetrazolyl, benzoxazolyl, imidazopyridinyl, 1,3-benzoxazinyl, 1,3-benzothiazinyl, oxazolopyridinyl, benzofuranyl, quinolinyl, quinazolinyl, quinoxalinyl, sulfolanyl, dihydroquinazolinyl, benzothiazolyl, phthalimido, benzofuranyl, azepinyl, oxazepinyl, thiazepinyl, tetrahydrofuryl, diazepinyl and benzodiazepinyl.
Amino groups may be substituted for example by one or two R1 groups, or two substituents can form a ring, preferably a 5 to 7-membered ring, which may be substituted and may contain other heteroatoms, for example morpholine, thiomorpholine, or piperidine. This ring can be substituted as for heterocyclyl.
The term acyl includes the residue of sulfur and phosphorus-containing acids as well as carboxylic acids. Examples of acyl groups are thus -COR5, -COOR5, -CXNR5R6, -CON(R5)OR6, -COONR5R6, -CON(R5)NR6R7, -COSR5, -CSSR5, -S(O)pR5, -S(O)2OR5, -S(O)pNR5R6, -P(xe2x95x90X)(OR5)(OR6), -CO-COOR5, where R5, R6 and R7, which may be the same or different, are hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted phenyl or optionally substituted heterocyclyl, or R5 and R6, or R6 and R7, together with the atom(s) to which they are attached can form a ring, p is 1 or 2 and X is O or S.
We have found that compounds of the invention wherein Z is oxygen are particularly effective in combating fungi.
Preferred R1 groups are hydrogen, 2l-oxotetrahydrofuranyl or optionally substituted alkyl. In particular when R1 is optionally substituted alkyl we have found C1-C5 alkyl groups. e.g. methyl, to be especially preferred. Preferred substituents are alkoxycarbonyl, alkanoyloxy, cyano and phenyl, itself optionally substituted by alkyl, alkoxy, haloalkyl or halogen.
R3 and R4 can be the same or different and are preferably hydrogen, halogen or optionally substituted alkyl, it is generally desirable that one of R3 or R4, is halogen, especially bromine or chlorine, and particularly bromine, and the other it hydrogen. In particular when R3 or R4 is optionally substituted alkyl, we have found C1-C5 alkyl groups, especially tert.-butyl, to be most active. When R3 or R4 is substituted alkyl, preferred substituents are halogen, e.g. trifluoromethyl.
Although good activity has been shown for each fused ring system, generally the thieno[3,2-d]pyrimidine ring system is preferred.
The compounds of the invention have activity as fungicides, especially against fungal diseases of plants, e.g. mildews and particularly cereal powdery mildew (Erysiphe graminis) and vine downy mildew (Plasmopara viticola), rice blast (Pyricularia oryzae), cereal eyespot (Pseudocercosporella herpotrichoides), rice sheath blight (Pellicularia sasakii), grey mould (Botrytis cinerea), damping off (Rhizoctonia solani), wheat brown rust (Puccinia recondita), late tomator or potato blight (Phytophthora infestans), apple scab (Venturia inaequalis), glume blotch (Leptosphaeria nodorum). Other fungi against which the compounds may be active include other powdery mildews, other rusts, and general pathogens of Deuteromycete, Ascomycete, Phycomycete and Basidiomycete origin.
The invention thus also provides a method of combating fungi at a locus infested or liable to be infested therewith, which comprises applying to the locus a compound of formula I.
The invention also provides an agricultural composition comprising a compound of formula I in admixture with an agriculturally acceptable diluent or carrier.
The composition of the invention may of course include more than one compound of the invention.
In addition, the composition can comprise one or more additional active ingredients, for example compounds known to possess plant-growth regulant, herbicidal, fungicidal, insecticidal or acaricidal properties. Alternatively the compound of the invention can be used in sequence with the other active ingredient.
The diluent or carrier in the composition of the invention can be a solid or a liquid optionally in association with a surface-active agent, for example a dispersing agent, emulsifying agent or wetting agent. Suitable surface-active agent include anionic compounds such as a carboxylate, for example a metal carboxylate of a long chain fatty acid; an N-acylsarcosinate; mono- or di-esters of phosphoric acid with fatty alcohol ethoxylates or salts of such esters; fatty alcohol sulfates such as sodium dodecyl sulfate, sodium octadecyl sulfate or sodium cetyl sulfate; ethoxylated fatty alcohol sulfates; ethoxylated alkylphenol sulfates; lignin sulfonates; petroleum sulfonates; alkyl-aryl sulfonates such as alkyl-benzene sulfonates or lower alkylnaphthalene sulfonates, e.g. butyl-naphthalene sulfonate; salts of sulfonated naphthalene-formaldehyde condensates; salts of sulfonated phenol-formaldehyde condensates; or more complex sulfonates such as the amide sulfonates, e.g. the sulfonated condensation product of oleic acid and N-methyl taurine or the dialkyl sulfosuccinates, e.g. the sodium sulfonate of dioctyl succinate. Nonionic agents include condensation products of fatty acid esters, fatty alcohols, fatty acid amides or fatty-alkyl- or alkenyl-substituted phenols with ethylene oxide, fatty esters of polyhydric alcohol ethers, e.g. sorbitan fatty acid esters, condensation products of such esters with ethylene oxide, e.g. poloxyethylene sorbitan fatty acid esters, block copolymers of ethylene oxide and propylene oxide, acetylenic glycols such as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, or ethoxylated acetylenic glycols.
Examples of a cationic surface-active agent include, for instance, an aliphatic mono-, di-, or polyamine as an acetate, naphthenate or oleate; an oxygen-containing amine such as an amine oxide or poloxyethylene alkylamine; an amine-linked amine prepared by the condenstaion of a carboxylic acid with a di- or polyamine; or a quaternary ammonium salt.
The compositions of the invention can take any form known in the art for the formulation of agrochemicals for example, a solution, a dispersion, an aqueous emulsion, a dusting powder, a seed dressing, a fumigant, a smoke, a dispersible powder, and emulsifiable concentrate or granules. Moreover it can be in a suitable form for direct application or as a concentrate or primary composition which requires dilution with a suitable quantity of water or other diluent before application.
An emulsifiable concentrate comprises a compound of the invention dissolved in a water-immiscible solvent which is formed into an emulsion with water in the presence of an emulsifying agent.
A dusting powder comprises a compound of the invention intimately mixed and ground with a solid pulverulent diluent, for example, kaolin.
A granular solid comprises a compound of the invention associated with similar diluents to those which may be employed in dusting powders, but the mixture is granulated by known methods. Alternatively it comprises the active ingredient absorbed or adsorbed on a pre-granular diluent, for example, Fuller""s earth, attapulgite or limestone grit.
Wettable powders, granules or grains usually comprise the active ingredient in admixture with a suitable surfactant and an inert powder diluent such as china clay.
Another suitable concentrate is a flowable suspension concentrate which is formed by grinding the compound with water or other liquid, a wetting agent and a suspending agent.
The concentration of the active ingredient in the composition of the present invention, as applied to plants is preferably within the range of 0.0001 to 1.0 per cent by weight, especially 0.0001 to 0.01 per cent by weight. In a primary composition, the amount of active ingredient can vary widely and can be, for example, from 5 to 95 per cent by weight of the composition.
In the method of the invention, the compound is generally applied to seeds, plants or their habitat. Thus, the compound can be applied directly to the soil before, at or after drilling so that the presence of active compound in the soild can control the growth of fungi which may attack seeds. When the soil is treated directly the active compound can be applied in any manner which allows it to be intimately mixed with the soil such as by spraying, by broadcasting a solid form or granules, or by applying the active ingredient at the same time as drilling by inserting it in the same drill as the seeds. A suitable application rate is within the range of from 5 to 1000 g per hectare, more preferably from 10 to 500 g per hectare.
Alternatively, the active compound can be applied directly to the plant by, for example, spraying or dusting either at the time when the fungus has begun to appear on the plant or before the appearance of fungus as a protective measure. In both such cases the preferred mode of application is by foliar spraying. It is generally important to obtain good control to fungi in the early stages of plant growth as this is the time when the plant can be most severely damaged. The spray or dust can conveniently contain a pre- or post-emergence herbicide if this is thought necessary. Sometimes, it is practicable to treat the roots of a plant before or during planting, for example, by dipping the roots in a suitable liquid or solid composition. When the active compound is applied directly to the plant a suitable rate of application is from 0.025 to 5 kg per hectare, preferably from 0.05 to 1 kg per hectare.
In addition, the compounds of the invention can be applied to plants, or parts thereof, which have been genetically modified to exhibit a trait such as fungal and/or herbicidal resistance.
The general formula I covers thieno[3,2-d]pyrimidine derivatives II, thieno[3,4-d]pyrimidine derivatives III, and thieno[2,3-d]pyrimidine derivatives IV. 
Compounds of formula IId, i.e. compounds of general formula II where R1 is hydrogen and Z is oxygen, can be prepared from compound V in two steps according to reaction Scheme 1. compounds of formula V may be prepared by a number a methods: see for example references and reviews in Comprehensive Heterocyclic Chemistry. Eds Katritsky AR and Rees C. W. (4), 863-934 and Comprehensive Heterocyclic Chemistry II, Eds Katritzky A. R. Rees C. W. and Scriven E. F. V. (2) 607-678.
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IId, i.e. compounds of general formula II where R1 is hydrogen, Z is oxygen, R3 is a group inert to lithium diisopropylamide and R4 is a substituent E, can be prepared in four steps from IIe according to reaction Scheme 2 wherein E is introduced using electrophilic substitution. Reaction conditions for introducing substituent E involve treatment of intermediate VIII with lithium diisopropylamide followed by addition of a suitable electrophile source. For example when E is -CH(R)OH, CH, bromine or methyl, the electrophile source is respectively, RC(xe2x95x90O)H, tosyl cyanide, N-bromosuccinimide or methyl iodide. When the group E is -CH(R)OH, elimination of water may occur to form the corresponding compound II where E is alkenyl. 
Compounds of formula IIf, i.e. compounds of formula II where R1 is hydrogen and Z is sulfur can, be made in two steps from IIa, by reaction with phosphorus oxychloride followed by treatment with sodium hydrosulfide according to reaction Scheme 3.
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIg, i.e. compounds of general formula II where R3 is a halogen, can be prepared according to reaction Scheme 4. When the halogen is bromine or chlorine, preferred reaction conditions comprise reacting IIh with bromine or chlorine in glacial acetic acid. 
Compounds of formula IIb, i.e. compounds of formula II where Z is oxygen, can be prepared from compounds of formula IIa, i.e. compounds of formula II where Z is oxygen and R1 is hydrogen, by reacting IIa with base followed by treatment with R1X where x is a leaving group. For example when R1 is alkyl, preferred reaction conditions comprise treating IIa with sodium hydride followed by an alkyl iodide (Scheme 5). 
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIi, i.e. compounds of formula II where R1 is hydroxy and Z is oxygen, may be prepared in three steps starting from compound V according to reaction Scheme 6. 
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similiar manner.
Compounds of formula IIj, i.e. compounds of formula II where R1 is RaO, may be prepared according to Scheme 7 by reacting compounds of formula IIk, with a suitable base, preferably sodium hydride followed by RaX, where X is a leaving group. 
Equivalent compound of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIm, i.e. compounds of formula II where R1 is acyloxy, may be prepared according to Scheme 8 by reacting compounds of formula IIk with the corresponding acyl chloride. 
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIn, i.e. compounds of general formula II where R1 is NH2 and Z is oxygen, can be prepared by reacting compounds of formula IX with hydrazine hydrochloride according to reaction Scheme 9. See Scheme 6 for the preparation of IX. 
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIp, i.e. compounds of general formula II where R1 is NH-acyl, can be prepared by reacting compounds of formula IIq with the corresponding acyl halide according to reaction Scheme 10.
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of formula IIr, i.e. compounds of general formula II where R1 is -Nxe2x95x90CHR and Z is oxygen, can be prepared according to reaction Scheme 11. R is preferably an aromatic group and Rd is preferably a lower alkyl group. 
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Compounds of IIs, i.e. compounds of general formula III where R3 is bromine, can be prepared by treating compound of formula IIt with bromine in glacial acetic acid heated under reflux for 2 hours. Continued heating for 5 hours gives the dibrominated compound IIIu, where R3 and R4 are both bromine (Scheme 12). 
Compounds of general formuls IIb, i.e. compounds of formula II where Z is oxygen, can be converted to teh corresponding compounds IIv where Z is sulfur by reaction with P2S5. The reaction is shown in Scheme 13.
Equivalent compounds of general formula III and IV can be made mutatis mutandis in similar manner.
Other methods will be apparent to the chemist skilled in the art as will be the methods for preparing starting materials and intermediates.
The invention is illustrated in the following Examles. Structures of isolated novel compounds were confirmed by NMR and/or other appropriate analyses.